The present invention relates to a spray pretreatment system comprising a spraying tunnel, in which is provided a treating station with treating installations for the treatment of workpieces by spraying or flooding, the treating installations being supplied with a treating liquid from a tank located below the station, and further comprising a conveyor for transporting workpieces through the spraying tunnel.
The invention further relates to a method for the spray pretreatment of workpieces where the workpieces are transported through a spraying tunnel and are treated with liquid from treating installations in at least one treating station and where the workpieces are fed in through an inlet opening.
A device and a method of the kind described above are known from DE 43 33 932 A1.
Systems of that kind serve for pre-treating workpieces with liquids and chemicals before the workpieces are subjected to a painting treatment or a color powder coating process, for example. A typical pretreatment consists, for example, of a cleaning operation where the workpieces are initially treated with a cleaning liquid before they are rinsed in several stations. In order to permit efficient cleaning, the cleaning liquid is supplied, preferably, at an increased temperature of between 50 and 70° C., for example. As a rule, the workpieces are transported through the spray pretreatment system using a continuously driven conveyor.
Given the fact that such spray pretreatment systems mostly have large passage openings, the resulting energy consumption is of course relatively high. As the workpieces are fed into the system through the inlet opening in horizontal direction, and as it is practically impossible, due to the continuously moving conveyor, to close off the inlet opening from ambient air, it is necessary to arrange a correspondingly sized extraction fan in the roof area of the spray pretreatment system. This leads to quite considerable energy demands.